Bausa said police negotiators had tried to end the crisis peacefully, but Zepeda instead shot his captives and later committed suicide.

"The cadaver of the suspect was also found at the ground floor. He has a bullet wound in the head and there's an indication that he shot himself," Bausa said.

The nature of the argument that prompted the hostage taking remained unknown, but initial investigation showed that Zepeda had a history of drug abuse, police said.

Bausa said Zepeda was also a known gun enthusiast as was his father.

"The assumption was... that he was fully armed," he said, explaining why police did not immediately assault the suspect's home.

The killings underscored the need for stricter gun controls in the Philippines, where a thriving weapons black market makes it easy for anyone to buy unlicensed firearms.

In January last year, a drugs-crazed gunman armed with a semi-automatic weapon killed eight people in a shooting rampage in a town just south of Manila.

The killings had sparked a government drive against illegal firearms, although months later police said there remained a staggering more than half a million unlicensed guns in the hands of civilians in the country.